This invention relates to log bunks of the class used for retaining logs on logging vehicles. Although it is intended for use primarily on log trucks, it may be adapted for use on railroad cars or other means of log conveyance.
Vehicles employed in transporting logs are provided with two or more bunks extending transversely of the vehicle at spaced intervals and provided at their ends with stakes for retaining the loaded logs. After the load has been transported to its destination and is ready to be discharged, the stakes are latch-released, permitting the logs to roll off. Because of the great weight and cumbersome character of the logs, their transportation and discharge in this manner obviously is dangerous, and many accidents are caused by failure of the bunk or stake mechanism.
The prior art latching systems used in the operation of these releasable stakes, are generally of two types. One type utilizes spring biasing or other return means to return the latch to a latched position automatically after release of the stakes. This type of latching mechanism is shown in my prior patent U.S. Pat. No. 3,033,542. Latching mechanisms of this class normally are contained inside the stake.
The second type of latching mechanism commonly used employs positive means for latching and unlatching the stake. Positive latching systems in general have required certain portions of the latching mechanism to be placed outside the stake, or have required that the stakes be offset from one another longitudinally of the vehicle to accommodate the latching mechanism.
The present invention, on the other hand, provides a positive stake latching mechanism which is totally enclosed in the bunk stake body, thereby leaving the stake exterior free to accomodate necessary attachments, such as lights and piggy-back carriers. In addition, the stakes can be mounted on the bunk without being longitudinally offset from each other, thereby increasing the load which they are capable of carrying. Furthermore, mounting the latch release mechanism inside the stake keeps the mechanism clear of debris and other foreign matter, and protects it from physical damage during loading and unloading operations.
Lastly, most prior art release type stakes cannot be removed from the logging vehicle bunks without expending considerable time and expense. This is disadvantageous since the stakes become damaged from time to time due to their necessarily rough usage. Their removal and replacement accordingly quite often are required. Also, when long stakes are used in certain types of logging operations, their removal frequently is desired to minimize clearance problems when the vehicle is travelling piggy-back and unloaded.
Accordingly, the general object of the present invention is to provide a log bunk having releasable stakes operated by a positive latching mechanism totally enclosed within the stake.
It is a further object of the present invention to provide a log bunk with positively latching, releasable stakes wherein the stakes are not longitudinally offset from one another.
It is a further object of the present invention to provide such a latching mechanism which can be operated alternatively from either side of the vehicle.
It is a further object of the present invention to provide a latching mechanism for releasable stakes wherein damage to or breakage of one of the latching elements will not cause the stakes to become unlatched.
It is a further object of the present invention to provide releasable stakes which can be easily removed from the bunk if desired.